From patchwork Wed Jan 20 18:28:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 12033315 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77A43C43333 for ; Wed, 20 Jan 2021 18:33:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F390233FA for ; Wed, 20 Jan 2021 18:33:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404444AbhATSdy (ORCPT ); Wed, 20 Jan 2021 13:33:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:51574 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404092AbhATSan (ORCPT ); Wed, 20 Jan 2021 13:30:43 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7902023436; Wed, 20 Jan 2021 18:28:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611167337; bh=+Q07rdmXpG22lqNBhxPmweCQkkGVvYg73pF3isz4/1Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vPCQV5p/mLfszt2Enn4i430s1vm/MSCrWzGYTiPZUg65JpOr0j61MOlT0pHp9Oq5X Wec9cHi47VjtsJvvhZKQvk4GOQtq0BVy2OeMejxxx9p19LhHLbmvPx57YioLaBwttL mFoq67WOBuMqeoGSm4suc+ZDqLtLtdCumWhzFk8zn+vr35IADd9AOWmxW2xxaBTMRK UV7K9im3re8wwNpdayCcOIbDJIzpIcJKaHfLG/+dwBm7UIscqdnlOcHqr9GOWFRZpU EAIdAUZi3P+yWR1XOEHmZBZQXQzT1oYO+agY2sL04PjntaucVUjwIhjhQnGooetoKU IxWGpGYJgplwQ== From: Jeff Layton To: ceph-devel@vger.kernel.org Cc: linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [RFC PATCH v4 13/17] ceph: add support to readdir for encrypted filenames Date: Wed, 20 Jan 2021 13:28:43 -0500 Message-Id: <20210120182847.644850-14-jlayton@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210120182847.644850-1-jlayton@kernel.org> References: <20210120182847.644850-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org Add helper functions for buffer management and for decrypting filenames returned by the MDS. Wire those into the readdir codepaths. Signed-off-by: Jeff Layton --- fs/ceph/crypto.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++ fs/ceph/crypto.h | 41 ++++++++++++++++++++++++++ fs/ceph/dir.c | 62 +++++++++++++++++++++++++++++++-------- fs/ceph/inode.c | 38 ++++++++++++++++++++++-- 4 files changed, 202 insertions(+), 15 deletions(-) diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c index f037a4939026..7ddd434c5baf 100644 --- a/fs/ceph/crypto.c +++ b/fs/ceph/crypto.c @@ -107,3 +107,79 @@ int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, ceph_pagelist_release(pagelist); return ret; } + +/** + * ceph_fname_to_usr - convert a filename for userland presentation + * @fname: ceph_fname to be converted + * @tname: temporary name buffer to use for conversion (may be NULL) + * @oname: where converted name should be placed + * @is_nokey: set to true if key wasn't available during conversion (may be NULL) + * + * Given a filename (usually from the MDS), format it for presentation to + * userland. If @parent is not encrypted, just pass it back as-is. + * + * Otherwise, base64 decode the string, and then ask fscrypt to format it + * for userland presentation. + * + * Returns 0 on success or negative error code on error. + */ +int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, + struct fscrypt_str *oname, bool *is_nokey) +{ + int ret; + struct fscrypt_str _tname = FSTR_INIT(NULL, 0); + struct fscrypt_str iname; + + if (!IS_ENCRYPTED(fname->dir)) { + oname->name = fname->name; + oname->len = fname->name_len; + return 0; + } + + /* Sanity check that the resulting name will fit in the buffer */ + if (fname->name_len > FSCRYPT_BASE64_CHARS(NAME_MAX)) + return -EIO; + + ret = __fscrypt_prepare_readdir(fname->dir); + if (ret) + return ret; + + /* + * Use the raw dentry name as sent by the MDS instead of + * generating a nokey name via fscrypt. + */ + if (!fscrypt_has_encryption_key(fname->dir)) { + oname->name = kmemdup(fname->name, fname->name_len, GFP_KERNEL); + oname->len = fname->name_len; + if (is_nokey) + *is_nokey = true; + return 0; + } + + if (fname->ctext_len == 0) { + int declen; + + if (!tname) { + ret = fscrypt_fname_alloc_buffer(NAME_MAX, &_tname); + if (ret) + return ret; + tname = &_tname; + } + + declen = fscrypt_base64_decode(fname->name, fname->name_len, tname->name); + if (declen <= 0) { + ret = -EIO; + goto out; + } + iname.name = tname->name; + iname.len = declen; + } else { + iname.name = fname->ctext; + iname.len = fname->ctext_len; + } + + ret = fscrypt_fname_disk_to_usr(fname->dir, 0, 0, &iname, oname); +out: + fscrypt_fname_free_buffer(&_tname); + return ret; +} diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h index 331b9c8da7fb..5a3fb68eb814 100644 --- a/fs/ceph/crypto.h +++ b/fs/ceph/crypto.h @@ -11,6 +11,14 @@ #define CEPH_XATTR_NAME_ENCRYPTION_CONTEXT "encryption.ctx" +struct ceph_fname { + struct inode *dir; + char *name; // b64 encoded, possibly hashed + unsigned char *ctext; // binary crypttext (if any) + u32 name_len; // length of name buffer + u32 ctext_len; // length of crypttext +}; + #ifdef CONFIG_FS_ENCRYPTION /* @@ -37,6 +45,22 @@ static inline void ceph_fscrypt_free_dummy_policy(struct ceph_fs_client *fsc) int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, struct ceph_acl_sec_ctx *as); +static inline int ceph_fname_alloc_buffer(struct inode *parent, struct fscrypt_str *fname) +{ + if (!IS_ENCRYPTED(parent)) + return 0; + return fscrypt_fname_alloc_buffer(NAME_MAX, fname); +} + +static inline void ceph_fname_free_buffer(struct inode *parent, struct fscrypt_str *fname) +{ + if (IS_ENCRYPTED(parent)) + fscrypt_fname_free_buffer(fname); +} + +int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, + struct fscrypt_str *oname, bool *is_nokey); + #else /* CONFIG_FS_ENCRYPTION */ static inline void ceph_fscrypt_set_ops(struct super_block *sb) @@ -55,6 +79,23 @@ static inline int ceph_fscrypt_prepare_context(struct inode *dir, struct inode * return 0; } +static inline int ceph_fname_alloc_buffer(struct inode *parent, struct fscrypt_str *fname) +{ + return 0; +} + +static inline void ceph_fname_free_buffer(struct inode *parent, struct fscrypt_str *fname) +{ +} + +static inline int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, + struct fscrypt_str *oname, bool *is_nokey) +{ + oname->name = fname->name; + oname->len = fname->name_len; + return 0; +} + #endif /* CONFIG_FS_ENCRYPTION */ #endif diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index 20943769438c..236c381ab6bd 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -9,6 +9,7 @@ #include "super.h" #include "mds_client.h" +#include "crypto.h" /* * Directory operations: readdir, lookup, create, link, unlink, @@ -241,7 +242,9 @@ static int __dcache_readdir(struct file *file, struct dir_context *ctx, di = ceph_dentry(dentry); if (d_unhashed(dentry) || d_really_is_negative(dentry) || - di->lease_shared_gen != shared_gen) { + di->lease_shared_gen != shared_gen || + ((dentry->d_flags & DCACHE_NOKEY_NAME) && + fscrypt_has_encryption_key(dir))) { spin_unlock(&dentry->d_lock); dput(dentry); err = -EAGAIN; @@ -313,6 +316,8 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx) int err; unsigned frag = -1; struct ceph_mds_reply_info_parsed *rinfo; + struct fscrypt_str tname = FSTR_INIT(NULL, 0); + struct fscrypt_str oname = FSTR_INIT(NULL, 0); dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos); if (dfi->file_info.flags & CEPH_F_ATEND) @@ -340,6 +345,10 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx) ctx->pos = 2; } + err = fscrypt_prepare_readdir(inode); + if (err) + goto out; + spin_lock(&ci->i_ceph_lock); /* request Fx cap. if have Fx, we don't need to release Fs cap * for later create/unlink. */ @@ -360,6 +369,14 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx) spin_unlock(&ci->i_ceph_lock); } + err = ceph_fname_alloc_buffer(inode, &tname); + if (err < 0) + goto out; + + err = ceph_fname_alloc_buffer(inode, &oname); + if (err < 0) + goto out; + /* proceed with a normal readdir */ more: /* do we have the correct frag content buffered? */ @@ -387,12 +404,14 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx) dout("readdir fetching %llx.%llx frag %x offset '%s'\n", ceph_vinop(inode), frag, dfi->last_name); req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS); - if (IS_ERR(req)) - return PTR_ERR(req); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto out; + } err = ceph_alloc_readdir_reply_buffer(req, inode); if (err) { ceph_mdsc_put_request(req); - return err; + goto out; } /* hints to request -> mds selection code */ req->r_direct_mode = USE_AUTH_MDS; @@ -405,7 +424,8 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx) req->r_path2 = kstrdup(dfi->last_name, GFP_KERNEL); if (!req->r_path2) { ceph_mdsc_put_request(req); - return -ENOMEM; + err = -ENOMEM; + goto out; } } else if (is_hash_order(ctx->pos)) { req->r_args.readdir.offset_hash = @@ -426,7 +446,7 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx) err = ceph_mdsc_do_request(mdsc, NULL, req); if (err < 0) { ceph_mdsc_put_request(req); - return err; + goto out; } dout("readdir got and parsed readdir result=%d on " "frag %x, end=%d, complete=%d, hash_order=%d\n", @@ -479,7 +499,7 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx) err = note_last_dentry(dfi, rde->name, rde->name_len, next_offset); if (err) - return err; + goto out; } else if (req->r_reply_info.dir_end) { dfi->next_offset = 2; /* keep last name */ @@ -507,22 +527,37 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx) } for (; i < rinfo->dir_nr; i++) { struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i; + struct ceph_fname fname = { .dir = inode, + .name = rde->name, + .name_len = rde->name_len, + .ctext = rde->altname, + .ctext_len = rde->altname_len }; + u32 olen = oname.len; BUG_ON(rde->offset < ctx->pos); + BUG_ON(!rde->inode.in); ctx->pos = rde->offset; dout("readdir (%d/%d) -> %llx '%.*s' %p\n", i, rinfo->dir_nr, ctx->pos, rde->name_len, rde->name, &rde->inode.in); - BUG_ON(!rde->inode.in); + err = ceph_fname_to_usr(&fname, &tname, &oname, NULL); + if (err) { + dout("Unable to decode %.*s. Skipping it.\n", rde->name_len, rde->name); + continue; + } - if (!dir_emit(ctx, rde->name, rde->name_len, + if (!dir_emit(ctx, oname.name, oname.len, ceph_present_ino(inode->i_sb, le64_to_cpu(rde->inode.in->ino)), le32_to_cpu(rde->inode.in->mode) >> 12)) { dout("filldir stopping us...\n"); - return 0; + err = 0; + goto out; } + + /* Reset the lengths to their original allocated vals */ + oname.len = olen; ctx->pos++; } @@ -577,9 +612,12 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx) dfi->dir_ordered_count); spin_unlock(&ci->i_ceph_lock); } - + err = 0; dout("readdir %p file %p done.\n", inode, file); - return 0; +out: + ceph_fname_free_buffer(inode, &tname); + ceph_fname_free_buffer(inode, &oname); + return err; } static void reset_readdir(struct ceph_dir_file_info *dfi) diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 2854711e8988..9863a8818132 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -1659,7 +1659,8 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req, struct ceph_mds_session *session) { struct dentry *parent = req->r_dentry; - struct ceph_inode_info *ci = ceph_inode(d_inode(parent)); + struct inode *inode = d_inode(parent); + struct ceph_inode_info *ci = ceph_inode(inode); struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info; struct qstr dname; struct dentry *dn; @@ -1669,6 +1670,8 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req, u32 last_hash = 0; u32 fpos_offset; struct ceph_readdir_cache_control cache_ctl = {}; + struct fscrypt_str tname = FSTR_INIT(NULL, 0); + struct fscrypt_str oname = FSTR_INIT(NULL, 0); if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) return readdir_prepopulate_inodes_only(req, session); @@ -1720,14 +1723,36 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req, cache_ctl.index = req->r_readdir_cache_idx; fpos_offset = req->r_readdir_offset; + err = ceph_fname_alloc_buffer(inode, &tname); + if (err < 0) + goto out; + + err = ceph_fname_alloc_buffer(inode, &oname); + if (err < 0) + goto out; + /* FIXME: release caps/leases if error occurs */ for (i = 0; i < rinfo->dir_nr; i++) { + bool is_nokey = false; struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i; struct ceph_vino tvino; + u32 olen = oname.len; + struct ceph_fname fname = { .dir = inode, + .name = rde->name, + .name_len = rde->name_len, + .ctext = rde->altname, + .ctext_len = rde->altname_len }; + + err = ceph_fname_to_usr(&fname, &tname, &oname, &is_nokey); + if (err) { + dout("Unable to decode %.*s. Skipping it.", rde->name_len, rde->name); + continue; + } - dname.name = rde->name; - dname.len = rde->name_len; + dname.name = oname.name; + dname.len = oname.len; dname.hash = full_name_hash(parent, dname.name, dname.len); + oname.len = olen; tvino.ino = le64_to_cpu(rde->inode.in->ino); tvino.snap = le64_to_cpu(rde->inode.in->snapid); @@ -1758,6 +1783,11 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req, err = -ENOMEM; goto out; } + if (is_nokey) { + spin_lock(&dn->d_lock); + dn->d_flags |= DCACHE_NOKEY_NAME; + spin_unlock(&dn->d_lock); + } } else if (d_really_is_positive(dn) && (ceph_ino(d_inode(dn)) != tvino.ino || ceph_snap(d_inode(dn)) != tvino.snap)) { @@ -1848,6 +1878,8 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req, req->r_readdir_cache_idx = cache_ctl.index; } ceph_readdir_cache_release(&cache_ctl); + ceph_fname_free_buffer(inode, &tname); + ceph_fname_free_buffer(inode, &oname); dout("readdir_prepopulate done\n"); return err; }